The present invention relates to elastomeric gaskets and, more specifically, to locking gaskets for providing a seal between a pair of tubular members, particularly corrugated pipe.
It is well known to form a seal between two pipe sections where the end of one of the pipe sections has annular grooves and one of the pipe sections has an enlarged bell portion. Some prior art elastomeric gasket 5 are placed around the end of the pipe section having annular grooves. The pipe section having annular grooves is inserted into an enlarged bell portion of a second pipe section. The elastomeric gasket contacts each of the pipe sections to form a seal between the pipe sections.
Some prior art gaskets are adapted to fit in the groove of a corrugated pipe or pipe connector. As one end of a pipe is pushed into the enlarged end of another pipe section or pipe connector, the gasket is sometimes pulled from the groove and the pipe is not properly sealed. When the pipe is not properly sealed ground water may leak into the pipe or fluid may leak out of the pipe and contaminate the ground.
U.S. Pat. No. 4,702,502 attempted to solve the problem where the gasket was pulled from the annular grooves of a corrugated pipe when the corrugated pipe was inserted into a bell portion of a second corrugated pipe. The ""502 patent concerns a telescopic joint in low pressure corrugated plastic pipes. The joint includes a one piece elastomeric gasket that has a sealing portion adapted to be disposed in a groove in one of the pipes and an anchoring portion adapted to be disposed in an adjacent groove. As the pipes are telescoped together the anchoring portion is trapped in the groove and anchors the sealing portion in place as it is compressed.
U.S. Pat. No. 3,796,447 to de Putter concerns a corrugated pipe connector for connecting ends of two male pipes. A rubber sealing ring is maintained in a corrugation of the pipe connector by a maintaining ring. The maintaining ring avoids removal of the sealing ring from the corrugation of the pipe connector during insertion of the male pipe ends into the corrugated pipe connector.
U.S. Pat. No. 4,834,398 to Guzowski et al. concerns a pipe sealing gasket having a first portion formed out of a hard, relatively high durometer material and a second portion formed of a relatively lower durometer, more flexible material. The harder first portion of the gasket is contacted first as the pipes are assembled, causing the gasket to maintain its position during assembly.
Typically, gaskets between two corrugated pipes do not securely lock the corrugated pipes together once they are assembled. A gasket is needed which includes an integral locking member that holds a gasket portion in place during assembly of two pipes and securely locks the pipes together once they are assembled.
The present invention is directed to a locking annular gasket for providing a seal between a first tubular member having an annular groove and an adjacent ridge and a smooth annular section of a second member, when the first member and the smooth annular section of the second member are in a relative surrounded a surrounding relationship. The locking annular gasket includes an annular gasket portion and a locking member. The annular gasket portion seals a gap between the first tubular member and the annular section of the second member when the first tubular member and the smooth annular section are in a relative surrounded and surrounding relationship. The locking member is secured to the gasket portion for holding the annular gasket portion in place while the first tubular member and the smooth annular section are being brought into a relative surrounded and surrounding relationship.
In one embodiment, the locking member includes a locking arm that extends into the annular groove of the first tubular member when the first tubular member and the smooth annular section are in a relative surrounded and surrounding relationship. The locking arm locks the first tubular member and the smooth annular section together. In one embodiment the annular gasket portion and the locking member are co-extruded. In this embodiment, the annular gasket portion and the locking members are made from materials having different durometers, wherein the locking member is made from a material having a durometer that is greater than the durometer of the material that the annular gasket portion is made from. In one embodiment, the locking member is made from a rigid material. In another embodiment the locking member is made from a more flexible material. In one embodiment, the locking member is made from the same material that the second tubular member is made from. The locking member may include notches to facilitate forming a locking annular gasket having an annular shape. In one embodiment sections of the locking member are cut away from the annular gasket portion to form discrete locking cleats about the circumference of the annular gasket portion. In one embodiment, the annular gasket portion includes a sealing portion having a cross-section that is generally round.
The locking annular gasket is used to provide a seal between a first tubular member having an annular groove and an adjacent ridge, and a smooth annular section of a second member. In one embodiment, the locking annular gasket is attached to the smooth annular section of the second member. The first tubular member and the smooth annular section are brought into alignment. The first tubular member and the smooth annular section are relatively moved toward one another to bring the first tubular member and the smooth annular section into a relative surrounded and surrounding relationship. The locking gasket is moved with respect to the first tubular member to engage the locking member with a corrugation ridge. The locking member is deformed by the corrugation ridge until the locking member is moved passed the ridge. Once the locking member moves passed the ridge, the locking member springs into the groove of the first annular member. As the locking member is moved with respect to the first annular member, the annular gasket portion moves into engagement with the first tubular member and the smooth annular section to provide a seal between the first and second members.
In a second embodiment, the locking is placed around the first tubular member with a locking arm of the locking member extending into a corrugation groove. The first tubular member is aligned with the second annular member. The first tubular member is relatively moved toward the smooth annular section to bring the first member and the second member into a relative surrounded and surrounding relationship. The first member is moved with respect to the second member to move the locking member into a smooth annular recess of the second member and to move the gasket portion into engagement with the first tubular member and the second tubular member to provide a seal between the first and second members.
In one embodiment, discrete portions of the locking member are attached to the smooth annular section. In one embodiment, relative movement of the first tubular member with respect to the second tubular member is inhibited by engaging the ridge with the locking arm of the locking member.